> > Hi Tom and Yaun, > > > > Just wanted to catch up on a few things: > > > > OCEANS: > > > > The Aggregate grids by time didn't link Paul Holland's grid to his model > > output. IDV says 'AggregationExisiting: no coordinate variable for agg > > dimension= Time > > > > I've contacted Paul Holland about his Antarctic Ocean model netCDF files - > > I think our computer is ultimately too underpowered to handle this (see > > next item) and I've asked if he can create a smaller complete file or even > > make a visualisation himself. > > > > I tried here to download these data, and I had to give up after a couple > hours waiting, the ftp is to slow. > > > > I downloaded a set of month averages (theta) from the ECCO2 server. > > > > Ecco2.jpl.nasa.gov/data1/cube/cube92/lat_lon/quart_90S_90N/THETA_monthly.nc/ > > > > Each one is about 200 MB. I can load one it and it looks good, but a second > > time step doesn't seem to load in. No error comes up, but I suspect the > > computer can't handle rendering the volume of data. I've experimented with > > adjusting the stride to less levels (every other fifth point) so that > > there's less for the computer to deal with, but this doesn't even produce > > an image. I should point out that I switched to a newer macbook pro with > > the i7 core (still 4 GB ram). > > > > This dataset is more interesting to me. My IDV has 10G memory and no problem > to deal with the volume display, such as isosurface. > If you see any problem with the memory, you can do the strike. > > > I got the same aggregation error trying to link up the different months > > into one time frame - is this because they're netCDF and IDV prefers doing > > this with GRIB? > > > > I think this is the problem of the IDV, we probably check the time dimension > variable in lower case, but this dataset using upper case for the time > dimension variable, I attached a ncml file you can reference. If you want to > load a series of file, you can modify this ncml file, it should be easy to > understand and change its content, otherwise, let me know. > Sorry, I forgot the attachment. Yuan > > Also I select to make a 3D isosurface (the idea being to pick out the dense > > bottom water which is at about -1.5 degrees C and below) but it produces a > > 'flat' surface, it's still undulating in 3D but doesn't have a thickness. > > This is presumably because that's how the data works, but is there a way of > > selecting an isosurface over a range, i.e -1.5 degrees C and below? > > > > > You need to change the vertical scaling to see the 3D effect, the default > scale is 16km, you can try to use 3000m, the change icon is in the viewpoint > tool bar on the left side of the map view window. > > > I'm currently getting access to another model that gives a years worth of > > data at 80 MB, hopefully our Mac will be able to handle this. > > > > DUST: > > > > I'm really keen to try and make a better visualisation of this, any further > > advice on how to adjust the scale to get more detail? > > > I would suggest you to check a few sample bundles already available in the > IDV: > > Data Choosers > catalogs > > select or enter: http://www.unidata.ucar.edu/georesources/idvcatalog.xml > > select IDV catalog > Unidata's RAMADDA Server > IDV Community Resources > > Bundles > NOAA CSI > > and find a few examples, and double click on it, when the open bundle window > popup, click ok, the IDV will bring up the display to play with. > > > Yuan > > > > > Also, do you know what might be wrong to stop it making a nice isosurface, > > or is just the nature of the data (very variable over a logarithmic scale!) > > > > AIR CURRENTS > > > > Thanks for pointing me towards NCDC, should hopefully be able to make some > > nice yearly visualisations with their archived data (if the computer can > > handle it!) > > > > COMPUTER: > > > > Any tips on improving performance? I've got a feeling the Mac isn't liking > > the JAVA script (is IDV running on a JAVA background, I seen a JAVA error > > come up a few times it's crashed?) > > > > Would it be more stable on a PC? > > > > Thanks, > > > > Dom > > > > > > > > > > > > > > > > -----Original Message----- > > From: Unidata IDV Support [mailto:address@hidden] > > Sent: 01 October 2011 17:30 > > To: Rees-Roberts, Dominic > > Cc: address@hidden; Rees-Roberts, Dominic > > Subject: [IDV #IYO-548353]: Request for links to hurricane bundles > > > > > Hi Dom, > > > > > > re: > > > > Thanks for the guide, the precipitable water, when displayed as > > > > described, > > > > looks great. I've been trying look at the various settings as I've gone > > > > along to pick up a few hints and tips. > > > > > > > Do you know off hand where this data comes from? > > > > > > The data is from the Global Forecast System (GFS) model. The display I > > > outlined used the 0.5 degree (55 km) resolution. > > > > > > re: > > > > It would be great to get precipitable water with a longer time frame. > > > > > > One can get LOTS of this data at the U.S. National Climactic Data Center > > > (NCDC). The process is straightforward: register an email address > > > and then select the type of data desired, parameters in that data (subset > > > of the full set of parameters that are possible), and times. The files > > > will be put on disk for you to FTP. > > > > > > re: > > > > I've also been busy trying to find and visualise various models and > > > > couple > > > > of issues/questions have popped up. > > > > > > > > There are four models I'm keen to try and display at the moment: > > > > > > > > 1) The Antarctic current model generated by Paul Holland at the British > > > > Antarctic Survey, that I mentioned before > > > > 2) The Antarctic atmospheric model (AMPS) produced by Jordan Powers at > > > > UCAR > > > > 3) Global dust output produced by Natalie Mahowald at Cornell > > > > 4) Global current model ECCO2 generated at JPL NASA > > > > > > OK. > > > > > > re: > > > > 1) I'm still waiting to find out from Paul what the original output > > > > was. He > > > > did say that the 10 GB file didn't include grid points and sent through > > > > another file which he uses to map the data out (grid file). Below are > > > > the > > > > details for our FTP site, Paul's files are saved into the 'Holland' > > > > folder. > > > > As you mentioned, downloading a 10 GB file probably isn't the best, the > > > > grid > > > > file is about 1 GB. > > > > > > This is easily doable. > > > > > > re: > > > > It maybe that I just need to link the two files - they're both .nc? > > > > > > This should be possible using the "aggregate by time" feature. > > > > > > re: > > > > To upload/download files externally: > > > > ftp://Earthfromspace5575:address@hidden > > > > > > > > FTP client details: > > > > > > > > username: xxxx > > > > password: xxxx > > > > URL: ftp.endemoluk.com > > > > > > Thanks. > > > > > > re: > > > > 2) Jordan has uploaded a bit of the AMPS output for me to look at, it's > > > > only > > > > a portion (1.7 GB) of the total output that we'd be interested in and > > > > came > > > > as a .tar.gz file. Jordan has since taken the file off of his server, > > > > but > > > > it's in the Powers folder of our FTP if you fancy taking a look. > > > > > > > > After unzipping I end up with a list of .nc files for hourly time points > > > > which seem to load up fine. I was thinking of using isosurfaces set to a > > > > particular wind speed to highlight the polar jet, I think I've seen > > > > something similar done by one of the visualisation teams at UCAR. How > > > > do I > > > > load multiple time points into IDV and tell IDV to put them into the > > > > same > > > > timeline? > > > > > > The current output of AMPS and 4 days previous is made available online on > > > our motherlode.ucar.edu demonstration server: > > > > > > motherlode.ucar.edu > > > > > > RAMADDA Data Repository > > > http://motherlode.ucar.edu/repository > > > > > > Projects > > > http://motherlode.ucar.edu/repository/entry/show/RAMADDA/Projects?entryid=1c0cb8d1-5177-4028-b685-577cbbf44ef6 > > > > > > Antarctic IDD > > > http://motherlode.ucar.edu/repository/entry/show/RAMADDA/Projects/Antarctic+IDD?entryid=2c55cb2c-82ff-4c1f-8215-1fdb14ae46da > > > > > > The model output is available in GRIB in the folders under AMPS Model > > > Output. > > > This is available directly in the IDV through the Catalogs selection. > > > > > > re: > > > > 3) Natalie has shared her global dust model output. These are relatively > > > > small files and can be found here: > > > > > > > > http://www.geo.cornell.edu/eas/PeoplePlaces/Faculty/mahowald/fordominic/ > > > > > > > > I'm particularly interested in DSTQ.00.nc as this contains data in 3 > > > > dimensions. What I'd like to do is try and select an isosurface that > > > > shows > > > > how the dust rises and travels across the Atlantic (and other > > > > locations). > > > > The problem is that IDV doesn't seem to identify the Z component and > > > > gives > > > > it a null value. I can display each level individually though. > > > > > > We will take a look to see what my be missing from the file(s). > > > > > The dataset is 280m in size, I will check it out next week from office. > > > > > re: > > > > Also, the dust range is fairly logarithmic, at the lower levels there > > > > are > > > > very small differences in dust concentration (e-12 to e-11) and when the > > > > default colour bar is used (in this range) you see nice eddies in the > > > > dust > > > > movement. However at higher levels the dust is in the e-8 range and the > > > > standard linear colour bar doesn't resolve the fine detail in the very > > > > low > > > > concentrations. > > > > > > Yuan will need to comment on this. > > > > > > > The color table is linear, however, we should be able to pick up some > > details in the dataset through applying the certain scaling factor. > > > > > re: > > > > Failing being able to visualise this in 3D I was thinking of displaying > > > > each > > > > level individually, which our CGI team can stack and fill in the gaps. > > > > Ideally the colour scale would be consistent through each level and be > > > > able > > > > to show the fine detail throughout the e-12 to e-4 range. > > > > > > > > I'm guessing if isosurfaces are possible it's going to be limited to the > > > > higher dust concentrations and the detail would be lost anyway. Also, it > > > > might be a bit of a cheat showing values on the logarithmic scale, the > > > > finer > > > > stuff you wouldn't see! > > > > > > > > On a side note, how does IDV decide on the default values for the colour > > > > scale? > > > > > > A default is assigned for each dataset, and this can be changed by the > > > user. > > > I will let Yuan lead you through this. > > > > > > > Basically, there is a default xml table to assign the default color table > > and range. You can always make the change to this table, or select > > different table after the image being created. > > > > > re: > > > > And is there a way of browsing the values or a summary of the values > > > > in the data - like maximum and minimum values, mean distribution? > > > > > > Again, this is a question for Yuan. > > > > > The IDV do have a formula to find the max and min in the grid dataset, but > > only in the time dimension if I remember correctly. > > > > > > > > Yuan > > > re: > > > > 4) The ECCO2 directory can be found here: > > > > http://ecco2.jpl.nasa.gov/data1/cube/cube92/ > > > > > > > > I need to double check with the PI which are the most relevant data > > > > sets to > > > > work with (is THETA commonly temperature?). In any case the data are > > > > presented in individual time steps (like Jordan's AMPS output) and are > > > > .data > > > > files. Are these recognised by IDV? > > > > > > > > Sorry - loads of questions! I'm going to hold off finding more data > > > > sets, I > > > > think I'm better off getting to grips with these for the time being. > > > > > > I agree. It is best to learn enough to be able to use the IDV effectively > > > before drowning oneself in data. > > > > > > re: > > > > The Mac is struggling a bit, when I try to do a 'flythrough' it freezes > > > > and > > > > the various displays start going wrong. Even if Paul's 10 GB current > > > > file > > > > could be loaded I suspect it would crash. I guess it's a case of finding > > > > more RAM (8GB?) > > > > > > Since everything in the IDV is inherently 3D, one needs to have a LOT of > > > memory > > > if one is trying to use large datasets. Our development machines here in > > > the UPC typically have 24 GB or more of RAM and we don't find that to be > > > too much :-) > > > > > > re: > > > > Many thanks, > > > > > > No worries. > > > Cheers, > > > > > > Tom > > > -- > > > **************************************************************************** > > > Unidata User Support UCAR Unidata > > > Program > > > (303) 497-8642 P.O. Box > > > 3000 > > > address@hidden Boulder, CO 80307 > > > ---------------------------------------------------------------------------- > > > Unidata HomePage http://www.unidata.ucar.edu > > > **************************************************************************** > > > > > > > > > Ticket Details > > =================== > > Ticket ID: IYO-548353 > > Department: Support IDV > > Priority: Normal > > Status: Open > > > > > > > > > Ticket Details =================== Ticket ID: IYO-548353 Department: Support IDV Priority: Normal Status: Open
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